Wasn't trying to step on the toes of the shrimp source. Regardless of whether or not shrimp are shipped correctly, they can and do occasionally die from the stress. I have it happen all the time when ordering from experienced shrimpers. (I also occasionally receive foreign shipments that get tied up for up to 8 days and never lose a shrimp, so try that one on for size - almost doesn't seem fair)
I do find that I lose less shrimp when they've been allowed to 'rest' (for lack of a better term at the moment) for several weeks before getting shipped to me.
Cleaning the substrate the day before the shrimp arrived and testing things/doing a water change probably means things are safe. But you never really know. Just like it's tough to know if a shrimp died from stress during shipping.
On a similar note: I carried a package of PRL CRS with me to Flagstaff a few weeks ago and they were banged around like crazy during the trip. Opened them up and they were fully colored, happy, not bothered in the least. Last night I transferred a PRL CRS to my CBS tank for breeding (can't justify the expense of a high quality female CBS at the moment) and the second the CRS hit the transfer cup - even prior to drip acclimation - she faded like woah. Of course, she colored up within a couple minutes of moving into her new tank but it's indicative of how finicky shrimp can be.